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<h1 class="title">paintarea.cpp 示例文件</h1>
<span class="subtitle">tools/plugandpaint/app/paintarea.cpp</span>
<!-- $$$tools/plugandpaint/app/paintarea.cpp-description -->
<div class="descr"> <a name="details"></a>
<pre class="cpp">

  <span class="comment">/****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, you may use this file under the terms of the BSD license
  ** as follows:
  **
  ** &quot;Redistribution and use in source and binary forms, with or without
  ** modification, are permitted provided that the following conditions are
  ** met:
  **   * Redistributions of source code must retain the above copyright
  **     notice, this list of conditions and the following disclaimer.
  **   * Redistributions in binary form must reproduce the above copyright
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  **     distribution.
  **   * Neither the name of The Qt Company Ltd nor the names of its
  **     contributors may be used to endorse or promote products derived
  **     from this software without specific prior written permission.
  **
  **
  ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  ** &quot;AS IS&quot; AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.&quot;
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/</span>

  <span class="preprocessor">#include &quot;interfaces.h&quot;</span>
  <span class="preprocessor">#include &quot;paintarea.h&quot;</span>

  <span class="preprocessor">#include &lt;QMouseEvent&gt;</span>
  <span class="preprocessor">#include &lt;QPainter&gt;</span>

  PaintArea<span class="operator">::</span>PaintArea(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent) :
      <span class="type"><a href="qwidget.html">QWidget</a></span>(parent)
  {
      setAttribute(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>WA_StaticContents);
      setAttribute(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>WA_NoBackground);

      theImage<span class="operator">.</span>fill(<a href="../qtgui/qcolor.html#qRgb">qRgb</a>(<span class="number">255</span><span class="operator">,</span> <span class="number">255</span><span class="operator">,</span> <span class="number">255</span>));
  }

  bool PaintArea<span class="operator">::</span>openImage(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&amp;</span>fileName)
  {
      <span class="type"><a href="../qtgui/qimage.html">QImage</a></span> image;
      <span class="keyword">if</span> (<span class="operator">!</span>image<span class="operator">.</span>load(fileName))
          <span class="keyword">return</span> <span class="keyword">false</span>;

      setImage(image);
      <span class="keyword">return</span> <span class="keyword">true</span>;
  }

  bool PaintArea<span class="operator">::</span>saveImage(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&amp;</span>fileName<span class="operator">,</span> <span class="keyword">const</span> <span class="type">char</span> <span class="operator">*</span>fileFormat)
  {
      <span class="keyword">return</span> theImage<span class="operator">.</span>save(fileName<span class="operator">,</span> fileFormat);
  }

  <span class="type">void</span> PaintArea<span class="operator">::</span>setImage(<span class="keyword">const</span> <span class="type"><a href="../qtgui/qimage.html">QImage</a></span> <span class="operator">&amp;</span>image)
  {
      theImage <span class="operator">=</span> image<span class="operator">.</span>convertToFormat(<span class="type"><a href="../qtgui/qimage.html">QImage</a></span><span class="operator">::</span>Format_RGB32);
      update();
      updateGeometry();
  }

  <span class="type">void</span> PaintArea<span class="operator">::</span>insertShape(<span class="keyword">const</span> <span class="type"><a href="../qtgui/qpainterpath.html">QPainterPath</a></span> <span class="operator">&amp;</span>path)
  {
      pendingPath <span class="operator">=</span> path;
  <span class="preprocessor">#ifndef QT_NO_CURSOR</span>
      setCursor(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>CrossCursor);
  <span class="preprocessor">#endif</span>
  }

  <span class="type">void</span> PaintArea<span class="operator">::</span>setBrushColor(<span class="keyword">const</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span> <span class="operator">&amp;</span>color)
  {
      <span class="keyword">this</span><span class="operator">-</span><span class="operator">&gt;</span>color <span class="operator">=</span> color;
  }

  <span class="type">void</span> PaintArea<span class="operator">::</span>setBrushWidth(<span class="type">int</span> width)
  {
      thickness <span class="operator">=</span> width;
  }

  <span class="type">void</span> PaintArea<span class="operator">::</span>setBrush(BrushInterface <span class="operator">*</span>brushInterface<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&amp;</span>brush)
  {
      <span class="keyword">this</span><span class="operator">-</span><span class="operator">&gt;</span>brushInterface <span class="operator">=</span> brushInterface;
      <span class="keyword">this</span><span class="operator">-</span><span class="operator">&gt;</span>brush <span class="operator">=</span> brush;
  }

  <span class="type"><a href="../qtcore/qsize.html">QSize</a></span> PaintArea<span class="operator">::</span>sizeHint() <span class="keyword">const</span>
  {
      <span class="keyword">return</span> theImage<span class="operator">.</span>size();
  }

  <span class="type">void</span> PaintArea<span class="operator">::</span>paintEvent(<span class="type"><a href="../qtgui/qpaintevent.html">QPaintEvent</a></span> <span class="operator">*</span> <span class="comment">/* event */</span>)
  {
      <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="keyword">this</span>);
      painter<span class="operator">.</span>drawImage(<span class="type"><a href="../qtcore/qpoint.html">QPoint</a></span>(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span>)<span class="operator">,</span> theImage);
  }

  <span class="type">void</span> PaintArea<span class="operator">::</span>mousePressEvent(<span class="type"><a href="../qtgui/qmouseevent.html">QMouseEvent</a></span> <span class="operator">*</span>event)
  {
      <span class="keyword">if</span> (event<span class="operator">-</span><span class="operator">&gt;</span>button() <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>LeftButton) {
          <span class="keyword">if</span> (<span class="operator">!</span>pendingPath<span class="operator">.</span>isEmpty()) {
              <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="operator">&amp;</span>theImage);
              setupPainter(painter);

              <span class="keyword">const</span> <span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span> boundingRect <span class="operator">=</span> pendingPath<span class="operator">.</span>boundingRect();
              <span class="type"><a href="../qtgui/qlineargradient.html">QLinearGradient</a></span> gradient(boundingRect<span class="operator">.</span>topRight()<span class="operator">,</span>
                                       boundingRect<span class="operator">.</span>bottomLeft());
              gradient<span class="operator">.</span>setColorAt(<span class="number">0.0</span><span class="operator">,</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(color<span class="operator">.</span>red()<span class="operator">,</span> color<span class="operator">.</span>green()<span class="operator">,</span>
                                              color<span class="operator">.</span>blue()<span class="operator">,</span> <span class="number">63</span>));
              gradient<span class="operator">.</span>setColorAt(<span class="number">1.0</span><span class="operator">,</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(color<span class="operator">.</span>red()<span class="operator">,</span> color<span class="operator">.</span>green()<span class="operator">,</span>
                                              color<span class="operator">.</span>blue()<span class="operator">,</span> <span class="number">191</span>));
              painter<span class="operator">.</span>setBrush(gradient);
              painter<span class="operator">.</span>translate(event<span class="operator">-</span><span class="operator">&gt;</span>pos() <span class="operator">-</span> boundingRect<span class="operator">.</span>center());
              painter<span class="operator">.</span>drawPath(pendingPath);

              pendingPath <span class="operator">=</span> <span class="type"><a href="../qtgui/qpainterpath.html">QPainterPath</a></span>();
  <span class="preprocessor">#ifndef QT_NO_CURSOR</span>
              unsetCursor();
  <span class="preprocessor">#endif</span>
              update();
          } <span class="keyword">else</span> {
              <span class="keyword">if</span> (brushInterface) {
                  <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="operator">&amp;</span>theImage);
                  setupPainter(painter);
                  <span class="keyword">const</span> <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> rect <span class="operator">=</span> brushInterface<span class="operator">-</span><span class="operator">&gt;</span>mousePress(brush<span class="operator">,</span> painter<span class="operator">,</span>
                                                                event<span class="operator">-</span><span class="operator">&gt;</span>pos());
                  update(rect);
              }

              lastPos <span class="operator">=</span> event<span class="operator">-</span><span class="operator">&gt;</span>pos();
          }
      }
  }

  <span class="type">void</span> PaintArea<span class="operator">::</span>mouseMoveEvent(<span class="type"><a href="../qtgui/qmouseevent.html">QMouseEvent</a></span> <span class="operator">*</span>event)
  {
      <span class="keyword">if</span> ((event<span class="operator">-</span><span class="operator">&gt;</span>buttons() <span class="operator">&amp;</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>LeftButton) <span class="operator">&amp;</span><span class="operator">&amp;</span> lastPos <span class="operator">!</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qpoint.html">QPoint</a></span>(<span class="operator">-</span><span class="number">1</span><span class="operator">,</span> <span class="operator">-</span><span class="number">1</span>)) {
          <span class="keyword">if</span> (brushInterface) {
              <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="operator">&amp;</span>theImage);
              setupPainter(painter);
              <span class="keyword">const</span> <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> rect <span class="operator">=</span> brushInterface<span class="operator">-</span><span class="operator">&gt;</span>mouseMove(brush<span class="operator">,</span> painter<span class="operator">,</span> lastPos<span class="operator">,</span>
                                                           event<span class="operator">-</span><span class="operator">&gt;</span>pos());
              update(rect);
          }

          lastPos <span class="operator">=</span> event<span class="operator">-</span><span class="operator">&gt;</span>pos();
      }
  }

  <span class="type">void</span> PaintArea<span class="operator">::</span>mouseReleaseEvent(<span class="type"><a href="../qtgui/qmouseevent.html">QMouseEvent</a></span> <span class="operator">*</span>event)
  {
      <span class="keyword">if</span> (event<span class="operator">-</span><span class="operator">&gt;</span>button() <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>LeftButton <span class="operator">&amp;</span><span class="operator">&amp;</span> lastPos <span class="operator">!</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qpoint.html">QPoint</a></span>(<span class="operator">-</span><span class="number">1</span><span class="operator">,</span> <span class="operator">-</span><span class="number">1</span>)) {
          <span class="keyword">if</span> (brushInterface) {
              <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="operator">&amp;</span>theImage);
              setupPainter(painter);
              <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> rect <span class="operator">=</span> brushInterface<span class="operator">-</span><span class="operator">&gt;</span>mouseRelease(brush<span class="operator">,</span> painter<span class="operator">,</span>
                                                        event<span class="operator">-</span><span class="operator">&gt;</span>pos());
              update(rect);
          }

          lastPos <span class="operator">=</span> <span class="type"><a href="../qtcore/qpoint.html">QPoint</a></span>(<span class="operator">-</span><span class="number">1</span><span class="operator">,</span> <span class="operator">-</span><span class="number">1</span>);
      }
  }

  <span class="type">void</span> PaintArea<span class="operator">::</span>setupPainter(<span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> <span class="operator">&amp;</span>painter)
  {
      painter<span class="operator">.</span>setRenderHint(<span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span><span class="operator">::</span>Antialiasing<span class="operator">,</span> <span class="keyword">true</span>);
      painter<span class="operator">.</span>setPen(<span class="type"><a href="../qtgui/qpen.html">QPen</a></span>(color<span class="operator">,</span> thickness<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>SolidLine<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>RoundCap<span class="operator">,</span>
                     <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>RoundJoin));
  }

</pre>
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<!-- @@@tools/plugandpaint/app/paintarea.cpp -->
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